Now, do not understand that you will be able to

[KLPNO]

Hello everyone,

Now, do not understand that you will be able to approach anyone, and, by simply willing and expecting the results, make that person do just what you will. You could do all of this if the person had no power of mental resistance, no Volic Force of his own to counteract yours. Some persons, unfortunately for themselves, have but little Volic Force, and are but puppets in the hands of those who know the secret of personal influence; others have a little more of the force, and so on, until the high stages are reached.

I'm not sure I understand the "Now, do not understand that you will be able to" part of the first sentence.
Does the first sentence mean "you can't make the other person do what you want by by simply willing and expecting the results or does it mean the opposite, i.e. that you can do that?

Thank you.

[5jj]

If you meet somebody who is talking abou the volic force, don't worry too much about the language. Even if the language makes sense, the ideas usually don't; be grateful if the language doesn't make sense - it spares you the effort of thinking about the (non-) ideas.

[KLPNO]

Thank you, fivejedjon.

[Raymott]

Hello everyone,

Now, do not understand that you will be able to approach anyone, and, by simply willing and expecting the results, make that person do just what you will. You could do all of this if the person had no power of mental resistance, no Volic Force of his own to counteract yours. Some persons, unfortunately for themselves, have but little Volic Force, and are but puppets in the hands of those who know the secret of personal influence; others have a little more of the force, and so on, until the high stages are reached.

I'm not sure I understand the "Now, do not understand that you will be able to" part of the first sentence.
Does the first sentence mean "you can't make the other person do what you want by by simply willing and expecting the results or does it mean the opposite, i.e. that you can do that?
You can't do it simply by doing that.
Thank you.

Putting aside issues of "Volic Force" - which I don't have the volic force to address - the phrase is easily understood.
"Do not understand" here is an imperative. It means, "Don't take it from what I've just said that ..."
"Now, don't assume that you can (will be able to) simply ..."

[KLPNO]

Thank you, Raymott.